An "offhand comment" refers to something that is said casually, without much thought or planning. It is usually a remark made without thinking deeply or considering the potential impact or consequences. Full definition
We've all made offhand comments about our addictive relationship with this or that game, our inability to put it down and the fact that sometimes «one more round» can turn into «Jesus, it's 3 am? (ludonarrativeassonance.com)
From not knowing where to send clients, to making offhand comments that should NEVER be made in the first place, the patient - provider aspect of the PFD story is crucial. (mindbodygreen.com)
It is hard to have that invalidated by offhand comments from either side of a debate. (realclimate.org)